Irradiation apparatus

ABSTRACT

An irradiation apparatus has at least one exchangeable radiation source that may be moved by means of a transport cable between at least one rest position and at least one irradiation position and a long-distance transport container for radiation sources to be exchanged. In order to reduce the danger of control errors, the rest position is located inside the long-distance transport container and the transport container forms or may form an integral part of the irradiation apparatus. For that purpose, interface elements are provided on the transport container and other parts of the irradiation apparatus. By winding and unwinding the transport cable on and from a feeding drum with a cable-receiving groove at least partially covered by a pressing strip, particularly thin transport cables may be used, so that the width of the pressing strip substantially corresponds to the width of the cable-receiving groove. The pressing strip is helically wound in the cable-receiving groove around the feeding drum, in the axial or radial direction with respect to the feeding drum, and the cable-receiving groove is thus covered in a substantially uninterrupted manner. Means for lifting, preferably also for deflecting and lowering again the pressing strip, may be moved along the transport cable in relation to the feeding drum in order to let free an output joint for the transport cable from the feeding drum.

The invention relates to an irradiation apparatus having at least oneexchangeable radiation source that can be moved between at least onenon-operative position and at least one radiating position by means of atransport cable, the apparatus further having a transport container fortransporting radiation sources to be exchanged.

An irradiation apparatus of this type is known from, for example,EP-B1-0 138 088, the content of which is incorporated by reference intothe disclosure of the present description.

The object of this known irradiation apparatus, which includes aplurality of radiation sources, is to simultaneously insert apredeterminable number of radiator holding elements into thecorresponding number of hollow probes by means of a single drive device.In one specific embodiment, the irradiation apparatus is equipped withonly as many radiation sources as are necessary for the therapy to beperformed in each treatment situation. For this purpose, the radiationsources are accommodated in small, easy-to-handle, flat cassettes thatcontain a radiation-source shield in addition to a drive-cable storagedrum. The individual cassettes are manually inserted with their flatsides close together into an easily-accessible cassette compartment suchthat the cassette housing latches with the irradiation apparatus in aclosely-adjacent arrangement. Therefore, for an individual radiationtherapy, it is only necessary to click the correct cassette combinationinto the irradiation apparatus. This relieves the treatment technicianof the task of transferring the radiator to be used from shieldedstorage containers into the irradiation apparatus and back as neededusing the transport cable, as was formerly the case. Because the flatcassettes must be compact and must be able to be coupled amongthemselves in the irradiation apparatus, they are not readily suitablefor long-distance transport, for example from and to themanufacturer/disposer. Hence, irradiation apparatuses of this typeadditionally necessitate a radiation-source transport container.

More stringent safety requirements are placed on generic irradiationapparatuses that are intended for use in intra-arterial irradiation toprevent a post-angioplasty restenosis. An irradiation apparatus of thistype and a treatment method are described in, among other publications,EP-A1-0 633 041. This publication is incorporated by reference into thedisclosure of the present patent application.

The known irradiation apparatuses are especially subject to a certainrisk of operator's error during exchange of the radiation source, sothat the radiation source can only be exchanged by specially trainedpersonnel. The radiation sources are supplied to the user in a transportcontainer that typically has two channels. The one channel serves toreceive the old radiation sources, that is, the sources to be exchanged,while the other channel serves to receive the fresh radiation source.The irradiation apparatus is connected to the empty channel of thetransport container by way of a transport hose. The transport cablesubsequently moves the radiation source to be exchanged into thetransport container. The drive-side end of the transport cable isdetached by the drive after the radiator-side end has been securedagainst sliding in the transport container. The transport hose issubsequently connected to the channel containing the fresh radiationsource, and the fresh radiation source is transferred into theirradiation apparatus in reverse order with respect to the old radiationsource. The exchange of radiation sources is a critical situation,because the radiation source is forced to exit the shield of theirradiation apparatus via the transport hose during the process, andbecause the transport cable must be completely detached and recoupled.In particular, any arbitrary radiation source can be drawn into theirradiation apparatus, so confusion or errors can occur over thewhereabouts of old or new radiation sources.

It is therefore the object of the invention to provide an irradiationapparatus in which the risk of an operator's error is reduced.

The solution is an irradiation apparatus having the features of claims1, 3 and/or 4.

In irradiation apparatuses of the invention, the user stores theradiation source in a shield block when the source is in its position ofnon-use (non-operative position), and--as a standard practice--thesource is moved into the radiating position by means of a transportcable. The shield surrounds the irradiation apparatus such that thetransmitted radiation of the irradiation apparatus then meets thespecifications for radiation-source containers regarding storage and useof the radiation sources. In accordance with the invention, theradiation-protection container (transport container) used forlong-distance transport of the radiation source between the supplier andthe user (client) serves as a component of the irradiation apparatusthat is or can be integrated. It is therefore inserted much like a key(transport container) into a lock (remaining part of the irradiationapparatus), for which purpose corresponding interface means areprovided. This feature creates a usable unit (irradiation apparatus)(claim 1). This prevents the radiation source from leaving its shield atthe user's (client's) location during the exchange, for example, for afresh radiation source. Furthermore, this feature can prevent confusionabout used or fresh radiation sources remaining in the apparatus,because a radiation source is associated with exactly one long-distancetransport container.

These properties of the apparatus are especially advantageous for theuser in that he can work with sources of different specifications (withrespect to activity, energy and geometry) without difficulty. Thus, itis readily possible to change from HDR to PDR (Pulse-Dose Rate) mode andto use a source that is optimally adapted to the application.

To avoid having to excessively increase the transport weight of atransport container of the invention, the transport container caninclude a shield that meets the specifications for long-distanceradiation-source transport containers, and the remaining part of theirradiation apparatus can have a shield that surrounds at least parts ofthe transport container such that, with respect to the non-operativeposition of the irradiation apparatus, the transmitted radiation of theapparatus meets (more rigorous) specifications for radiation-sourcestorage containers (claim 2). Of course, the shield of the long-distancetransport container can meet the specifications for radiation-sourcestorage containers in certain spatial directions, while it is notsufficiently strong in other spatial directions. This is a compromisebetween the transport, weight and the operator's comfort in insertingthe transport container into the irradiation apparatus.

The design of an irradiation apparatus of the invention can besimplified if the transport container has a spiral-shaped transportchannel that extends through, inside which the storage position islocated. The transport cable can enter at one end of the transportchannel, and be connected to an upstream drive, such as a storage drum.The transport cable pushes the radiation source from behind through thetransport channel to transfer the source from its non-operative positioninto its radiating position.

The irradiation apparatus shield that surrounds the transport containerin the operating position can include a shield hood, preferably one thatswings open. This simplifies the exchange of radiation sources, andensures that, after the transport container has been inserted into theirradiation apparatus, the entire shield meets the specifications forradiation-source storage containers.

As a further measure for avoiding operator's errors, means can beprovided for automatically locking the radiation source or the transportcable in a transport position during transport of the transportcontainer. This measure can prevent personnel from forgetting to lockthe radiation source prior to transport. The radiation source ortransport cable is preferably automatically locked when the transportcontainer is removed from the irradiation apparatus.

A transport-cable storage element, preferably a storage drum, onto orfrom which the transport cable is wound and unwound, respectively, canbe provided on the transport container. so the transport container and atransport-cable storage element, particularly a storage drum, arecombined to form a transport module (claim 3). With this measure, thetransport cable need not be separated from its drive unit fortransporting the radiation source, a procedure during which a widevariety of errors, particularly operator's errors, could occur. Ofcourse, the transport module can include further transport-cable drivemeans. It can be advantageous, however--especially with regard toweight--to provide transport-cable drive means, such as a mechanicaldrive, in the other part of the irradiation apparatus, which means areconnected to the transport module or transport-cable storage elementthrough suitable couplings when the transport module is inserted intothe other part of the irradiation apparatus. Of course, this couplingcan preferably be effected automatically. The modular unit comprisingthe transport container and the transport-cable storage element also hasthe advantage of increased precision in the determination of theradiator's position, because any manufacturing tolerances can be takeninto account as unalterable correction values, for example.

To increase safety, the transport module can include means for lockingthe storage drum, preferably automatically, during transport of thetransport module. This prevents an actuation of the transport-cabledrive during transport of the radiation source.

The locking means are preferably enabled automatically prior to theinitiation of movement of the radiation source from its non-operativeposition into the radiating position (claim 5). This prevents damage tothe assemblies of the irradiation apparatus of the invention, includingthe transport container or transport module. The locking means arepreferably enabled automatically upon the insertion of the transportmodule or transport container into the irradiation apparatus.

Extremely thin transport cables are required for gamma or beta radiationsources, particularly for irradiation in the vicinity of the heart.

Flexible sources having a highly flexible lead wire are advantageous inallowing radiation sources to be pushed through catheters havingextremely small bending radii (FIG. 15).

To prevent the transport cable from collapsing, for example, atransport-cable drive is proposed, with which even extremely thintransport cables can be driven without collapsing or looping. In thisinstance, the transport cable is wound onto or unwound from a storagedrum known per se and having a cable-receiving groove that is covered atleast partially by a pressing band; a novel pressing band on the part ofthe transport cable that is wound in spiral fashion onto the storagedrum is wound onto the storage drum, extensively parallel to thetransport cable (claim 4). The pressing band is comparatively narrow;the extension of its width only covers one winding of the transportcable. Thus, the transport cable can be wound in spiral fashion, in theaxial or radial direction, onto the storage drum. Consequently, thepressing band presses the transport cable until it occupies a very smallregion directly in front of the point from which the transport cable islifted from the storage drum into the cable-receiving groove. Incontrast to the pressing bands known from the prior art, in this casethe entire length of the transport cable that is wound onto the storagedrum is pressed onto the storage drum, that is, into the cable-receivinggroove, with practically negligible interruptions. To ensure that thecable is also guided without collapsing or looping in the region aroundthe lifting point of the transport cable from the storage drum, apressing roller and/or a cable-guiding part with which the transportcable can be lifted from the storage drum can be provided in thisregion. Of course, a pressing-band guidance of this type can be employedadvantageously, independently of the use of a cable-receiving groove.Thus, a transport-cable drive is created that can reliably driveextremely thin transport cables, for example those that are necessaryfor preventing post-angioplasty restenosis through intra-arterialirradiation.

In the region around the lifting point of the transport cable from thestorage drum, the pressing band can be guided, for example by means ofdeflection rollers, around the storage drum in the opposite direction ofthe winding direction of the storage drum. This can prevent unnecessarycrossings or deflections of the pressing band or the transport cable,and both the pressing band and the transport cable are extensivelyguided in a plane extending perpendicular to the shaft of the storagedrum.

For gentle handling of the radiation source and the transport cable inthe presence of obstacles in the transport cable, and particularly inthe event of operator's errors, the irradiation apparatus can include animpact sensor for monitoring the shearing force exerted on the transportcable (claim 9) a detection of obstacles in the transport channel isalready known per se from EP-A1-0 278 829. Of course, this impact sensorcan also be used advantageously, independently of the other features ofthe aforementioned irradiation apparatus.

While the impact sensor can include any means for monitoring shearingforce exerted on a cable, it is nevertheless advantageous for the impactsensor to include a region of the transport cable that is guided along acurve, as well as means for detecting a dislocation of the transportcable toward the outside of the curve (claim 8). Within the scope ofthis disclosure, the outside of the curve is understood to be the sideof the cable facing radially outwardly from the curve.

Any sensors, for example optical or electrical sensors, for detecting adislocation can serve as means for detecting the dislocation of a cable.The use of a mechanical switching contact and/or a proximity switch isespecially advantageous, however.

If the radiation source or the transport cable impacts an obstacle asthe radiation source advances, the transport cable in the region of thecurve is dislocated toward the outside of the curve. The naturalelasticity of the transport cable can suffice to prevent a dislocationof the transport cable toward the outside of the curve during normaloperation, so the means for detecting a dislocation are not dislocatedduring normal operation. It can be advantageous, however, for the impactsensor to include elastic means that counteract a dislocation of thetransport cable toward the outside of the curve. The shearing force tobe exerted on the transport cable can be set by the selection of thespring constant. Examples of such elastic means include elastic-bendingtubes that guide the transport cable. These tubes can also be rigid, butmovable with respect to the rest of the transport cable, and can beconnected to a retaining spring, for example a tension spring disposedon the inside of the curve. Of course, in a similar manner, atensile-force sensor can be provided that monitors a dislocation of thetransport cable toward the inside of the curve, for example. In such acase, elastic means can advantageously be provided that counteract thedislocation of the transport cable toward the inside of the curve.

In the use of a sensor that supplies an analog output signal fordeflecting the curved transport cable, it is possible to use a servoamplifier to drive an electromagnet as a restoring force such that thedeflection can be kept as small as desired. In this case, the servoamplifier supplies the signal necessary for monitoring the shearingforce.

Of course, the transport-cable impact monitoring of the invention thathas an impact sensor can also advantageously be used in irradiationapparatuses other than those described in claims 1, 3 and/or 4. A sensorhaving an analog output signal further permits a dynamic speedregulation:

The shortest possible extension time (<5 s) is necessary for minimizingthe stress due to radiation. As the extension time increases, however,the frictional forces between the transport cable and the guide hosealso increase, especially when the guide path has small radii ofcurvature.

The nominal value of the extension speed of the transport cable can beregulated with the analog sensor signal, corresponding to the frictionalforce, such that the shearing force exerted on the cable does not exceeda (cable-dependent), specific maximum value. Thus, an overstressing ofthe transport cable and the guide hose is prevented at thehighest-possible extension speed. The advancing movement is onlyinterrupted if the maximum permissible shearing force is exceeded at theminimum permissible extension speed. This dynamic speed regulation canalso advantageously be used in irradiation apparatuses other than thosedescribed in claims 1, 3 and/or 4.

To prevent erroneous switches of the radiation sources, the transportcontainer can include means, particularly electronic means, foridentifying its associated radiation source (claim 9). Of course, theseidentification means can also be used advantageously, independently ofthe other features of the irradiation apparatus. In particular, theseidentification means can include an electronic memory, preferably aserial EEPROM (claim 10). Notably, it is possible to connect the rest ofthe irradiation apparatus with these identification means, particularlyautomatically, so the present radiation source can be identified by theirradiation apparatus, namely by its electronics. The identificationmeans can also contain other data relating to the radiation source, suchas initial activity and starting date, or the like. The identificationmeans can also contain data relating to the transport container or thetransport module. These data can be, for example, the length or strengthof the transport cable. The identification means can likewise includedata relating to the storage drum or the transport-cable drive, such asits radius or the number of path-indicator pulses per mm of extensionpath. In this way, high positioning precision is possible, despitelow-cost production of the drive mechanics, which usually includescertain manufacturing tolerances, because the mechanical data can becompensated or settled by data contained by the identification means.

The shield can include assemblies comprising tungsten for meeting evenhigher shield requirements and increasing export opportunities, becausethis material possesses no characteristic radiation.

The aforementioned components are claimed and described in the exemplaryembodiments, and are to be used in accordance with the invention, arenot subjected to any exceptional conditions with regard to their size,shape, material selection and technical conception, so the selectioncriteria known in the respective field of use can be used withoutlimitations.

Further details, features and advantages of the subject of the inventionensue from the following description of the attached drawings, in whicha preferred embodiment of an irradiation apparatus of the invention isshown by way of example. Shown are in:

FIG. 1 schematically, a plan view of an irradiation apparatus of theinvention;

FIG. 2 the same irradiation apparatus in a side view, partially cut awayand partially in vertical section;

FIG. 3 the transport container according to FIG. 2 in an enlarged sideview, partially cut away;

FIG. 4 a front view of the transport module of FIGS. 1 through 3(schematically and partially in vertical section)--view A--A accordingto FIGS. 1 and 2;

FIG. 5 schematically, the transport module of FIGS. 1 and 4 with lockingmeans;

FIG. 6 the storage drum of the transport module of FIGS. 1 through 5, insection along the line VI--VI in FIG. 4;

FIG. 7 the securing of the transport cable and the pressing band to thestorage drum;

FIG. 8 a clamping device for the pressing band;

FIG. 9 schematically, the transport-cable drive means of the irradiationapparatus of FIG. 1;

FIG. 10 the drive connection between the pressing band, the drive andthe motor of the irradiation apparatus of FIG. 9, in section along theline X--X in FIG. 9;

FIG. 11 an impact sensor according to the invention;

FIG. 12 a transport-channel connector between the irradiation apparatusand a transport container;

FIG. 13 a plan view of the transport-channel connector of FIG. 12;

FIG. 14 the transport-channel connector of FIGS. 12 and 13, in sectionalong the line XIV--XIV in FIG. 13;

FIGS. 15A-C two embodiments of a transport cable with a radiationsource, in a side view (FIGS. 15A and 15B) and in cross-section (FIG.15C);

FIG. 16 an alternative specific embodiment of the transport-cableguidance (alternative to FIG. 6) in an enlarged, cut-out representationof the cable-receiving groove (section along the line XVI--XVI accordingto FIG. 17);

FIG. 17 a side view of the same specific embodiment of a storage drum;

FIG. 18 a storage drum of the same specific embodiment for the specificembodiment of FIG. 16 (partially in axial section along the lineXVIII--XVIII according to FIG. 19);

FIG. 19 a side view of the same storage drum (view A according to FIG.18); and

FIG. 20 a side view of a storage drum as an additional alternative tothe specific embodiment of FIG. 16.

As shown in FIG. 1, the irradiation apparatus has a carrier plate 10, onwhich a transport module 2 that has a transport container 20 isdisposed. Carrier plate 10 can pivot horizontally about a shaft 10' tofacilitate the removal and insertion of transport module 2 (theoutward-pivoted position is shown as a dashed line in FIG. 1). In theinward-pivoted state, the transport container is enveloped by anadditional shield 3. Additional shield 3 has an additional-shield half30, which is permanently connected to the irradiation apparatus, and anadditional-shield half 32, which can swing out by means of a hinge 31.The two additional-shield halves 30 and 32 are embodied such that, whenhinge 31 is in the open state, transport module 2 can pivot outward withcarrier plate 10. However, the cuts of the two additional-shield halves31 [sic] and 32 are configured such that the section planes do notintersect at least the storage position. of the radiation source, andpossibly even transport container 20 (as shown in FIG. 1 and preferredin this regard). This prevents radiation from exiting along the sectionplanes.

The irradiation apparatus further has a housing 11 for diverse drives,at least for a transport cable, and diverse control units.

Transport container 20 preferably includes an outside cylinder 21, whichis bored through eccentrically and preferably comprises tungsten, and inwhich an inside cylinder 22 fits. A spiral-shaped cable channel is cutinto the outside surface of inside cylinder 22. A transport andradiation-protection container of this type can also be usedadvantageously without the features of the dependent claims, and can bemanufactured simply. This spiral-shaped cable channel 23 exits transportcontainer 20 through a connecting cone 24 disposed on a surface of thecylinder formed by outside cylinder 21 and inside cylinder 22.

As FIG. 4 shows, transport module 2 has beneath its transport container20 a drive housing 25, in which assemblies for driving a transport cable4 are disposed. A radiation source 4' is disposed at one end oftransport cable 4. FIG. 4 shows radiation source 4' in its non-operativeposition.

Disposed in drive housing 25 is a storage drum 40, onto and from whichtransport cable 4 can be wound and unwound. As explained below,transport cable 4 is pressed on storage drum 40 by a pressing band 41. Apressing roller 42, by way of which pressing band 41 is lifted fromstorage drum 40, is provided in the region of lifting point 42'.Pressing band 41 is guided back to storage drum 40 by means ofdeflection rollers 43, 44 and 45 and a drive roller 46. As is preferred,the side of pressing band 41 that rests against drive roller 46 isembodied as a toothed belt, which assures reliable driving of pressingband 41, and thus of storage drum 40 and transport cable 4.

Behind lifting point 42', prior to entrance into transport container 20,transport cable 4 has a curved region, which forms a further impactsensor 5 that is described below.

During normal operation, pressing band 41 is driven by means of driveroller 46, so that transport cable 4 is unwound from storage drum 40. Inthis way, radiation source 4' is moved out of its non-operativeposition, through the spiral-shaped cable channel 23 and connecting cone24, and into a radiating position. Conversely, radiation source 4' canbe moved back into its non-operative position by corresponding drivingof drive roller 46.

For securing radiation source 4' in its transport position duringtransport of transport module 2, the source has a stop lever 60 (FIG. 5)and a stop 62 on drive housing 25, between which a pin 61 located onstorage drum 40 can be stopped when radiation source 4' is in itstransport position. Stop lever 60 is further connected to a stop rod 63,which, by means of a gear 64, can press a further stop rod 65 intospiral-shaped cable channel 23, thus stopping transport cable 4.

If transport module 2 is positioned on carrier plate 10, stop lever 60can be pivoted by means of an unlocking pin 66. This pivoting stipulatesthat stop rod 65 releases transport cable 4 (FIG. 5). This pivoting ofstop lever 60 also effects the release of storage drum 40 by pin 61(this released state has not yet been attained in the representation ofFIG. 5). If stop lever 60 has released pin 61, the storage drum canextend radiation source 4'. Storage drum 40 is displaced--as will beexplained below in connection with FIG. 6--as it rotates, that is,during the movement of transport cable 4 parallel to the shaft 79 of thestorage drum. Therefore, with respect to stop 62, pin 61 already hassufficient spacing to permit free rotation of storage drum 40 after onedrum rotation.

The spiral-shaped arrangement of pressing band 41 in a spiral-shapedcable-receiving groove 41' of storage drum 40 is shown schematically inFIG. 6. This figure shows pressing band 41 in section at the end ofcable-receiving groove 41'. While pressing band 41 is guided incable-receiving groove 41' over practically the entire length of thegroove, in FIG. 6, transport cable 4 is only wound in the left regiononto storage drum 40 (shown in a dashed line). In the region of liftingpoint 42' of the transport channel, pressing band 41 is also lifted fromstorage drum 40 by means of pressing roller 42 and deflection rollers43, 44 and 45 and drive roller 46. As shown particularly in FIG. 6,pressing band 41 extends essentially in a plane perpendicular tostorage-drum shaft 79. A guide part 49, which slides intocable-receiving groove 41', 41' as a guide shoe and is fixed to thehousing, forces rotating storage drum 40 to perform a relative movementwith respect to lifting point 42', so that storage drum 40 slides alongits shaft (shaft 79) in the illustrated, preferred exemplary embodiment.

Storage drum 40 is disposed to be displaced--namely, to slide--onstorage-drum shaft 79, as indicated by the double-headed arrow A. Inthis way, lifting point 42' and the positions of pressing roller 42,deflection rollers 43, 44, 45 and drive roller 46 remain stationary,while, at 46', pressing band 41 returns into the pressing position inthe part of cable-receiving groove 41" adjacent to lifting point 42.

Mounted on the one side of storage drum 40 (shown as a dashed line inFIG. 7) is a holding element 47 that has a clamping channel 47' fortransport cable 4 and a pressing-band holding element 47". Atransport-band clamp 47'" is also mounted on this side of the storagedrum, the clamp fixing transport band 4 with respect to storage drum 40.Mounted to the other side of storage drum 40 is a tensing device 48 forpressing band 41, which device includes a base plate 48' secured tostorage drum 40 by means of screws 48A and onto which a clamping plate48" having recesses that correspond to the toothing of the pressing bandis fastened by means of screws 48B, so that the toothing of pressingband 41 engages the recesses and, in this way, the band is fixed in itsposition.

As FIG. 9 shows, in a normal case, drive roller 46 and thus transportcable 4 are driven by way of a drive shaft 71 that is connected, fixedagainst relative rotation, to the roller, and a drive disk 71' that isconnected to the drive shaft. Drive disk 71' has a toothing, which isengaged by a toothed belt 72. During operation, toothed belt 72 runsover a drive disk 73' mounted on a motor 73. Motor 73 can move betweenan ON position and an OFF position by way of a tension spring 73" and apressure magnet 73'" such that, in the currentless state of pressuremagnet 73'", drive disk 73' does not engage toothed belt 72, whereaspressure magnet 73'" brings drive disk 73' into engagement with toothedbelt 72 during a current flux (FIG. 10). In an emergency, particularlyin a power failure, drive shaft 71 is separated from motor 73 by thismeasure, and can be moved freely, for example to rewind transport cable4 on storage drum 40. Even in the OFF position, removal of transportmodule 2 is very simple, because the module need not be separated fromthe transport-cable drive in a special step.

To permit transport cable 4 and thus radiation source 4' to be broughtinto, for example, the transport or non-operative position in anemergency, the irradiation apparatus has an emergency drive. Theemergency drive includes a coupling disk 79', which is connected to thestorage-drum shaft 79 embodied as a torque shaft. A second coupling disk78' is connected to a shaft 78, with shaft 78 being pressed withcoupling disk 78' against the first coupling disk 79' by means of acompression spring 77. In contrast, coupling disks 78' and 79' areseparated by means of a pull-type electromagnet 76, so that when currentflows through pull-type electromagnet 76, the emergency drive isseparated from the storage-drum shaft. Pull-type electromagnet 76 canrelease shaft 78 and thus couple in the emergency drive, particularly inthe case of a power failure, but also, for example, through manualoperation. For moving the transport cable, the emergency drive has acrank handle 74 and an emergency motor 75, which are connected to shaft78 by way of toothed wheels 78".

Of course, the individual features of the aforementioned transport-cabledrive can be used advantageously, independently of the other features ofthe irradiation apparatus.

Impact sensor 5 includes a curved region 50 of transport cable 4, whichis guided in this curved region 50 in two elbows 51, which preferablyhave a bending radius of 4 cm and are spaced slightly from one another.Elbows 51 rest against stops 51' on the inside of the curve, but can bedislocated into a hollow space 52 provided on the outside of the curve.A tension spring 53 holds elbows 51 in their position with respect tostops 51'. If transport cable 4 impacts an object as it advances, it hasthe tendency to be dislocated into hollow space 52, that is, toward theoutside of the curve. If the force exerted on elbows 51 by this movementexceeds the tensile force of tension spring 53, transport cable 4 andelbows 51 are dislocated into hollow space 52. This dislocation isdetected by a switch 54. Switch 54 transmits a signal to the electronicsof the irradiation apparatus, which prevents further pushing oftransport cable 4 through storage drum 40.

Transport container 20 has connecting cone 24, through whichspiral-shaped cable channel 23 exits, for ensuring a connection betweenspiral-shaped cable channel 23 of the transport container and aconnecting hose 29 that functions reliably and can be produced andreleased quickly. Moreover, the irradiation apparatus has a connectingcone 26, which can be placed onto connecting cone 24 (FIGS. 12 through14). To increase the operator's comfort and the operating reliability,connecting cone 26 is connected to the rest of the irradiation apparatusby means of a movable arm 27. To ensure precise placement of connectingcone 26 on connecting cone 24, connecting cone 26 is connected to arm 27by way of a cardan joint 28.

In the center, connecting cone 26 has a cable channel 29', whichtransitions into a connecting hose 29. Cable channel 29' is disposed ina connecting piece 26' that is connected to the rest of connecting cone26 by way of a ball bearing 26" for ensuring that connecting hose 29 canrotate with respect to connecting cone 26. The forces acting onconnecting hose 29 and the connection between connecting cone 26 andconnecting cone 24 can be reduced with this measure.

Of course, with this type of connection of a transport container 20 witha connecting hose 29, a reliably functioning, easy-to-operate connectionof a transport container 20 with a connecting hose 29 can also beeffected independently of the other features of the irradiationapparatus.

Extremely thin transport cables and short-range radiation sources infiber form, particularly beta radiators, as are basically known fromEP-A1-0 633 041, can be used with the storage drum according to theinvention having a spiral-shaped pressing band. FIG. 15A shows the tipof a transport cable 4 of this type, which can also be curved in aJ-shape, for example, for guiding a catheter around narrow curves. Aglued, pressed or welded point 4" produces the connection between thefiber-type radiation sources 4' and drive cable 4. FIG. 15B shows acorresponding radiation source without a guide tip, and FIG. 15C shows across-section.

In the specific embodiments of FIGS. 16 through 20, the spiral-typewinding of transport cable 4 and pressing band 41 respectively coveringonly one winding of the transport cable is effected in a radialdirection with respect to storage drum 40, so that transport cable 4 isguided narrowly between the part of an uninterrupted pressing band thatcovers and presses the cable radially from the outside and the radialoutside of the winding of pressing band 41 that is respectively closestto the shaft. For this purpose, the two radially outside surfaces ofpressing band 41 possess the complementary surface configuration thatcan be seen in FIG. 16, namely the preferred groove/spring arrangementof FIG. 16 that has a transport-cable guide groove 41A on the side ofthe "spring" 41B.

This transport-cable and pressing-band guidance can be effected invarious forms. For example, the part of the pressing band that does notyet cover or no longer covers the transport cable can be wound onto orunwound from a storage drum 40'. These specific embodiments areillustrated in FIGS. 17 through 20.

To take into consideration the different radii, such as inevitably occurat the exit point 42' of the transport cable from storage drum 40because of the "radial" unwinding process, in the specific embodiment ofFIG. 17, it is provided that the two storage drums 40 and 40' arerotatably seated on a common rocker 80, on shafts that are spaced fromone another. Exit point 42' remains fixed to the apparatus while storagedrums 40 and 40' are guided behind, about the rotation point 81 ofrocker 80 under the pulling force of a spring 82, corresponding to theincrease or decrease in the radius of transport cable 4 and pressingband 41.

The pressing band must guide the transport cable reliably under alloperating conditions. Therefore, the pressing band should be subjectedto a certain tensile stress. This tensile stress can be exerted, forexample, by flat coil springs located in storage spools 40 and 40',which springs counteract one another; the spring force of the restoringcoil should always be greater than the force of the advancing coil (FIG.17).

Another option is to generate the tensile stress through pre-stressedrollers that act on the pressing band (FIGS. 18 and 19). This is onlypossible, however, if the two spools 40 and 40' are mechanically coupledto one another. For this purpose, spools 40 and 40' are rotatablysecured on a common drive shaft 23 [sic] in the specific embodiment ofFIGS. 18 and 19. It is therefore necessary to dispose deflection rollers43, 44 and 45 of pressing band 41 such that the pressing band can beguided back and forth between the storage drums 40 and 40' disposed withaxial spacing--such as in a gear shift of a bicycle, but with onlydriving wheels and no driven wheels.

Because of the changeable winding diameter on storage drums 40 and 40',the relative speed of storage drums 40 and 40' must change duringwinding and unwinding of the pressing band if the guidance path ofpressing band 41 between the two storage drums is to be kept constant. Arelative speed corresponding to the winding diameter can be attainedwith a gear having two spiral-shaped toothed wheels Z3 and Z4 accordingto FIG. 20. When pressing band 41 is wound, for example, in ten layersfrom storage drum 40 onto storage drum 40', the total rotation path ofstorage drum 40 can be transformed into a single revolution of the twospiral-shaped toothed wheels Z3 and Z4 through a gear reduction of 10:1by means of toothed wheels Z1:Z2 or Z6:Z5. The variable transmissionratio of these two toothed wheels is selected such that the unwindingand winding speed of the two storage drums 40 and 40' is not a functionof the winding diameter.

    ______________________________________                                        LIST OF REFERENCE NUMERALS                                                    ______________________________________                                        10   carrier plate      41A    transport-cable                                10'  shaft                     guide groove                                   11   drive housing      41'    cable-receiving groove                          2   transport module   41"    cable-receiving groove                         20   transport container                                                                              41B    spring                                         21   outside cylinder   41C    groove                                         22   inside cylinder    42     pressing roller                                23   spiral-shaped cable channel                                                                      42'    exit point                                     24   connecting cone    43     deflection roller                              25   drive housing      44     deflection roller                              26   connecting cone    45     deflection roller                              27   arm                46     drive roller                                   28   cardan joint       47     holding element                                29   connecting hose    47'    clamping channel                               29'  cable channel of connecting cone                                                                 47"    pressing-band                                   3   additional shield         holding element                                30   additional-shield  48     tensing device                                      half, stationary   48'    base plate                                     31   hinge              48"    clamping plate                                 32   additional-shield half, hinged                                                                   48A    screws                                          4   transport cable    48B    screws                                          4'  radiation source   49     guide part                                      4"  glued, pressed or welded point                                                                    5     impact sensor                                  40   storage drum       50     curved region                                  40'  storage drum       51     elbows                                         41   pressing band      51'    stop                                           62   stop               52     hollow space                                   63   stop rod           53     tension spring                                 64   gear               54     switch                                         65   stop rod           60     stop lever                                     66   unlocking pin      61     pin                                            71   drive shaft                                                              71'  drive disk                                                               72   toothed belt                                                             73   motor                                                                    73'  drive disk                                                               73"  tension spring                                                           73'''                                                                              pressure magnet                                                          74   crank handle                                                             75   emergency motor                                                          76   pull-type electromagnet                                                  77   compression spring                                                       78   shaft                                                                    78'  coupling disk                                                            78"  toothed wheel                                                            79   storage-drum shaft                                                       79'  coupling disk                                                            80   rocker                                                                   81   rotation point                                                           82   spring                                                                   83   drive shaft                                                              ______________________________________                                    

Having thus described the invention, it is claimed:
 1. An irradiationapparatus having at least one exchangeable radiation source that can bemoved between at least one non-operative position, which is locatedinside of a shield in the irradiation apparatus, and at least oneradiating position, which is located outside of the shield, by means ofa transport cable, the apparatus further having a radiation-sourcetransport container for long-distance transport of exchangeableradiation sources completely separate from the irradiation apparatus,the improvement comprising the radiation-source transport containerbeing a component of the irradiation apparatus that is detachablyintegrated, and an interface means that allows the radiation-sourcetransport container to be integrated, being provided on the container,and on the other part of the irradiation apparatus, so theradiation-source transport container serves as a shield or a part of theshield of the irradiation apparatus in which the non-operative positionis located, wherein the irradiation apparatus has a shield thatsurrounds at least parts of the transport container and that thetransmitted radiation of the irradiation apparatus meets thespecifications for radiation-source storage containers when theradiation source is in its non-operative position.
 2. The irradiationapparatus as defined in claim 1, wherein, said transport cable storageelement includes a storage drum, onto or from which the transport cablecan be wound and unwound, respectively.
 3. The irradiation apparatus asdefined in claim 1, wherein the radiation-source transport container orthe transport module includes path indicators means for determining theposition of the radiation source.
 4. The irradiation apparatus asdefined in claim 1, wherein the radiation-source transport container(20) includes a tungsten shield that is bored through eccentrically. 5.The irradiation apparatus as defined in claim 1, including means forautomatically locking the radiation source or the transport cable in atransport position during transport of the radiation-source transportcontainer.
 6. The irradiation apparatus as defined in claim 1, includinga dynamic speed regulation of the transport cable in cooperation with asensor that detects traveling resistance.
 7. A method of intra-arterialirradiation for preventing a post-angioplasty or other potentialrestenosis, comprising the use of an irradiation apparatus as defined inclaim
 1. 8. The irradiation apparatus as defined in claim 1, wherein theradiation-source transport container or a transport module includes, asa component of the irradiation apparatus, electronic means foridentifying the radiation source and for identifying characterizingvariables of the storage drum.
 9. The irradiation apparatus as definedin claim 8, wherein the identification means includes an electronicmemory.
 10. The irradiation apparatus as defined in claim 1, wherein theradiation-source transport container comprises an outside cylinder, aninside cylinder that fits inside a bore in the outside cylinder, saidbore being disposed asymmetrically, and a spiral-shaped cable channelcut into the contact surface between the inside cylinder and the bore inthe outside cylinder, as a radially outer groove in the outside surfaceof the inside cylinder.
 11. The irradiation apparatus as defined inclaim 1, wherein the transport cable is wound onto or unwound from astorage drum having a cable-receiving groove that is at least partiallycovered by a pressing band, wherein the width of the pressing bandcorresponds to the width of the cable-receiving groove, that thepressing band is wound, in spiral fashion in the cable-receiving groove,around the storage drum in the axial or radial direction with respect tothe storage drum, and essentially covers the cable-receiving groovewithout interruption, and that a device for lifting, deflecting andrepositioning, the pressing band for freeing an exit point for thetransport cable to the storage drum can travel along the drum andrelative to it.
 12. The irradiation apparatus as defined in claim 1,wherein the irradiation apparatus further includes an impact sensor formonitoring the shearing force exerted on the transport cable.
 13. Anirradiation apparatus having at least one exchangeable radiation sourcethat can be moved between at least one non-operative position, which islocated inside of a shield in the irradiation apparatus, and at leastone radiating position, which is located outside of the shield, by meansof a transport cable, the apparatus further having a radiation-sourcetransport container for long-distance transport of exchangeableradiation sources completely separate from the irradiation apparatus,the improvement comprising the radiation-source transport containerbeing a component of the irradiation apparatus that is detachablyintegrated, and an interface means that allows the radiation-sourcetransport container to be integrated, being provided on the container,and on the other part of the irradiation apparatus, so theradiation-source transport container serves as a shield or a part of theshield of the irradiation apparatus in which the non-operative positionis located, wherein the radiation-source transport container or atransport module includes, as a component of the irradiation apparatus,electronic means for identifying the radiation source and foridentifying characterizing variables of the storage drum.
 14. Theirradiation apparatus as defined in claim 13, wherein the identificationmeans includes an electronic memory.
 15. The irradiation apparatus asdefined in claim 14, wherein the electronic memory is a serial EEPROM.16. The irradiation apparatus as defined in claim 13, wherein thetransport cable is wound onto or unwound from a storage drum having acable-receiving groove that is at least partially covered by a pressingband, wherein the width of the pressing band corresponds to the width ofthe cable-receiving groove, that the pressing band is wound, in spiralfashion in the cable-receiving groove, around the storage drum in theaxial or radial direction with respect to the storage drum, andessentially covers the cable-receiving groove without interruption, andthat a device for lifting, deflecting and repositioning, the pressingband for freeing an exit point for the transport cable to the storagedrum can travel along the drum and relative to it.
 17. The irradiationapparatus as defined in claim 13, wherein the radiation-source transportcontainer or the transport module includes path indicators means fordetermining the position of the radiation source.
 18. The irradiationapparatus as defined in claim 13, wherein the irradiation apparatusfurther includes an impact sensor for monitoring the shearing forceexerted on the transport cable.
 19. An irradiation apparatus having atleast one exchangeable radiation source that can be moved between atleast one non-operative position, which is located inside of a shield inthe irradiation apparatus, and at least one radiating position, which islocated outside of the shield, by means of a transport cable, theapparatus further having a radiation-source transport container forlong-distance transport of exchangeable radiation sources completelyseparate from the irradiation apparatus, the improvement comprising theradiation-source transport container being a component of theirradiation apparatus that is detachably integrated, and an interfacemeans that allows the radiation-source transport container to beintegrated, being provided on the container, and on the other part ofthe irradiation apparatus, so the radiation-source transport containerserves as a shield or a part of the shield of the irradiation apparatusin which the non-operative position is located, wherein theradiation-source transport container comprises an outside cylinder, aninside cylinder that fits inside a bore in the outside cylinder, saidbore being disposed asymmetrically, and a spiral-shaped cable channelcut into the contact surface between the inside cylinder and the bore inthe outside cylinder, as a radially outer groove in the outside surfaceof the inside cylinder.
 20. The irradiation apparatus as defined inclaim 19, wherein the radiation-source transport container including atungsten shield that is bored through eccentrically.
 21. The irradiationapparatus as defined in claim 18, including a dynamic speed regulationof the transport cable in cooperation with a sensor that detectstraveling resistance.
 22. The irradiation apparatus as defined in claim19, including means for automatically locking the radiation source orthe transport cable in a transport position during transport of theradiation-source transport container.
 23. An irradiation apparatushaving at least one exchangeable radiation source that can be movedbetween at least one non-operative position, which is located inside ofa shield in the irradiation apparatus, and at least one radiatingposition which is located outside of the shield, by means of a transportcable, the apparatus further having a radiation-source transportcontainer for long-distance transport of exchangeable radiation sourcescompletely separate from the irradiation apparatus, the improvementcomprising the radiation-source transport container being a component ofthe irradiation apparatus that is detachably integrated, and aninterface means that allows the radiation-source transport container tobe integrated, being provided on the container, and on the other part ofthe irradiation apparatus, so the radiation-source transport containerserves as a shield or a part of the shield of the irradiation apparatusin which the non-operative position is located, wherein the transportcable is wound onto or unwound from a storage drum having acable-receiving groove that is at least partially covered by a pressingband, wherein the width of the pressing band corresponds to the width ofthe cable-receiving groove, that the pressing band is wound, in spiralfashion in the cable-receiving groove, around the storage drum in theaxial or radial direction with respect to the storage drum, andessentially covers the cable-receiving groove without interruption, andthat a device for lifting, deflecting and repositioning, the pressingband for freeing an exit point for the transport cable to the storagedrum can travel along the drum and relative to it.
 24. The irradiationapparatus as defined in claim 23, wherein a guide part is provided inthe region of a transport-cable exit point and extends into thecable-receiving groove, and at least guides the transport cable into orout of the cable-receiving groove.
 25. The irradiation apparatus asdefined in claim 23, including a dynamic speed regulation of thetransport cable in cooperation with a sensor that detects travelingresistance.
 26. The irradiation apparatus as defined in claim 23,including means for automatically locking the radiation source or thetransport cable in a transport position during transport of theradiation-source transport container.
 27. The irradiation apparatus asdefined in claim 23, wherein the radiation-source transport containerincluding a tungsten shield that is bored through eccentrically.
 28. Anirradiation apparatus having at least one exchangeable radiation sourcethat can be moved between at least one non-operative position, which islocated inside of a shield in the irradiation apparatus, and at leastone radiating position, which is located outside of the shield, by meansof a transport cable, the apparatus further having a radiation-sourcetransport container for long-distance transport of exchangeableradiation sources completely separate from the irradiation apparatus,the improvement comprising the radiation-source transport containerbeing a component of the irradiation apparatus that is detachablyintegrated, and an interface means that allows the radiation-sourcetransport container to be integrated, being provided on the container,and on the other part of the irradiation apparatus, so theradiation-source transport container serves as a shield or a part of theshield of the irradiation apparatus in which the non-operative positionis located, said irradiation apparatus including an impact sensor formonitoring the shearing force exerted on the transport cable.
 29. Theirradiation apparatus as defined in claim 28, wherein the impact sensorincludes a region of the transport cable that is guided along a curve,and means for detecting a dislocation of the transport cable toward theoutside of the curve.
 30. The irradiation apparatus as defined in claim28, including a region of the transport cable that is at least curvedhas two free ends at an interruption point.
 31. The irradiationapparatus as defined in claim 30, including at least one restoringspring that acts on at least one of the free ends for establishing adeflection force.
 32. The irradiation apparatus as defined in claim 28,wherein the radiation-source transport container or the transport moduleincludes path indicators means for determining the position of theradiation source.
 33. The irradiation apparatus as defined in claim 28,wherein the radiation-source transport container includes a tungstenshield that is bored through eccentrically.
 34. The irradiationapparatus as defined in claim 28, including a dynamic speed regulationof the transport cable in cooperation with a sensor that detectstraveling resistance.
 35. The irradiation apparatus as defined in claim28, wherein the radiation-source transport container or a transportmodule includes, as a component of the irradiation apparatus, electronicmeans for identifying the radiation source and for identifyingcharacterizing variables of the storage drum.